Bluetooth is a low-cost, short-range (RF) links between mobile PCs, mobile phones and other portable devices. Bluetooth can transmit through solid, non-metal objects.

Short for British Naval Connector or Bayonet Nut Connector or Bayonet Neill Concelman, a type of connector used with coaxial cables such as the RG-58 A/U cable used with the 10BASE2 Ethernet system. The basic BNC connector is a male type mounted at each end of a cable. This connector has a center pin connected to the center cable conductor and a metal tube connected to the outer cable shield. A rotating ring outside the tube locks the cable to any female connector.

It is a notch or groove melted into the base metal next to the toe or root of a weld and left unfilled by weld metal.

It is the conductor used to connect  noncurrent- carrying  metal parts of equipment, raceways and others enclosures to the system grounding conductor at the service and / or the grounding electrode conductor.

Color CRTs add a metal grid in front of the phosphor coating called a shadow mask. It ensures that an electron gun assigned to one color doesn't strike a dot of another color.